Nothing says you don’t know the children’s market like querying a YA novel with a six year old protagonist or a fifteen year old middle grade.
When I read a query or submission that says something like this, I immediately know that the author is either new to children’s books and hasn’t done the research or they don’t care. Neither inspires a ton of confidence.
So, let’s get characters that are the right age for the different segments of the children’s market.
For picture books, that means your characters are going to be little kids. Usually in these books, the character’s age isn’t specified, but they generally act like preschoolers or kindergartners. Occasionally, they’ll be as old as first or second grade.
From there, kids begin independent reading into chapter books. (Think Magic Tree House or A to Z Mysteries kind of series books.) Here the characters are usually 6 or 7 or 8. The main character’s age should match the reader’s age. Kids at this age are very egocentric. They want to read about characters that are like themselves. So a book for six year olds will have a six year old main character. And so on.
Once they hit nine, most kids prefer to read about kids that are older than themselves. Since middle grade readers tend to be between the ages of 9-12, that means that most middle grade main characters range in age from 10-12. Ten falls on the younger side of middle grade, twelve on the older. You do get a few thirteen and even fourteen year olds, but they are rarer. What you almost never see is a kid that’s nine.
For YA, again, the kids are reading up. Most YA readers are thirteen to around eighteen although there are exceptions. You do get some kids as young as eleven reading some of the younger YA, and you also have some adults that read upper YA, especially the romance ones. However, the primary audience is considered to be teens 13-18. So, the character age tends to be 15-18 with 16 YOs for the younger end and 18 or even 19 or 20 YOs.
I encourage you to double check that your character age matches the type of book you’re submitting. And if for some reason it doesn’t, consider why that might be. Do you need to age your character up? Do you need to re-evaluate whether or not you’ve written a middle grade?
No matter what, show the world that you are familiar with the children’s market and how the age of main characters works within it.